Distribution of three psocid species (Psocoptera: Liposcelididae) in different moisture gradients in wheat

Psocids can cause considerable economic losses to stored products by direct feeding, and they have become global pests during the last two decades. We studied the distribution of Liposcelis bostrychophila Badonnel (Psocoptera: Liposcelididae), Liposcelis entomophila (Enderlein), and Liposcelis brunnea Motschulsky in different moisture gradients (11-12-13%, 11-13-15%, and 13-14-15%) and a control (13-13-13%) in wheat using a circular metal arena, which has a removable metal divider that partitioned it into three rings (outer, middle and inner). Lipsocelis bostrychophila and L. entomophila preferred grain with the highest moisture content in the different gradients evaluated. In general, populations of Liposcelis brunnea equally preferred grain with moisture contents greater than or equal to 13%. These results showed the moisture contents preferred for three of the main psocid pests of stored grains, and this could help in making better pest management decisions.